Amplifiers are an important building block in integrated circuit (IC) devices such as communications transmitters and receivers. Amplifiers are typically designed to provide a relatively constant gain to an input signal over a predetermined signal range, known as the linear operating range. When the amplifier input signal falls outside the linear operating range, the amplifier gain may significantly deviate from the nominal gain, leading to unwanted non-linearity and distortion at the amplifier output.
For portable communications devices such as mobile phones, the trend toward lower voltage power supplies has made it increasingly difficult to design amplifiers with adequate linear operating range. When delivering high output power, the gain of the constituent transistors in such amplifiers may decrease, causing gain compression of the amplifier.
It would be desirable to provide novel techniques for designing amplifiers with enhanced linear operating range.